Wet etched insulator and electronic circuit component

Abstract

The present invention relates to an insulator as an insulating layer in a laminate which can inhibit dusting at the time of use, more particularly an electronic circuit component to which the insulator has been applied, particularly a wireless suspension. The insulator comprises a laminate of one or more insulation unit layers etchable by a wet process, the insulator having been subjected to plasma treatment after wet etching. The insulator exists mainly as an insulating layer in a laminate having a layer construction of first inorganic material layer-insulating layer-second inorganic material layer or a layer construction of inorganic material layer-insulating layer, and at least a part of the inorganic material layer has been removed to expose the insulating layer.

1. A process for producing an insulator comprising the steps of:
 providing a laminate having a layer construction of a first adhesive polyimide, a low-expansion polyimide having a coefficient of linear thermal expansion of not more than 30 ppm and a second adhesive polyimide, 
 wet-etching the laminate to obtain the laminate having a wet etched portion and at least an end face of the wet etched portion thereof, and 
 plasma treating the wet-etched laminate to obtain an insulator in which the laminate has a plasma treated portion, said plasma treated portion comprising a strengthened etched end face in which atoms which have been cleaved by hydrolysis to an embrittled etched end face as a result of the wet etching have been boned together with neighboring atoms to form the strengthened etched end face. 
 
     
     
       2. The process according to  claim 1 , wherein the plasma treating is carried out for not less than 0.01 sec and not more than 30 min. 
     
     
       3. The process according to  claim 1 , wherein the plasma treating is carried out under the atmospheric pressure. 
     
     
       4. The process according to  claim 1 , wherein the plasma treating is carried out under reduced pressure. 
     
     
       5. The process according to  claim 1 , wherein the wet-etching is carried out with an etching liquid having a pH value of more than 7.0.